Polycarbonate resins are characterized by their transparency, mechanical strength and dimensional stability. These properties make polycarbonate an ideal choice for the preparation of sheets to be used in glazing and other outdoor applications. However, stabilizers and screening agents are required to lengthen the useful life of these sheets. These additives, while effective for the intended purpose cause other problems. Stain resistant panels made from polycarbonate have been described in U.S. Pat. No. 4,948,666, EP 338355, EP 320632 and EP 247480. Other related patents include Canadian Patent 1,208,873 which disclosed a polycarbonate-based panel made resistant to UV radiation. Accordingly, a panel is structured to include a core layer of polycarbonate to which there is adhesively bonded an intermediate UV absorption layer and a cover layer. The purpose of the cover layer is to prevent vaporization of the UV absorber from the intermediate layer. The intermediate, UV-absorption layer may be prepared from polycarbonate and contains derivatives of benzotriazole as UV absorbers. Also noted is German Patent Application 1,670,951 which disclosed polycarbonate molded articles, including ribbons which are rendered resistant to UV radiation by incorporating the bis-benzotriazole compound of the present invention therewith. A method for coating a polycarbonate sheet with a protective layer was disclosed in UK Patent Application 2,028,228. A layer preferably of polymethacrylate and advantageously containing a UV absorber is said to be applied to the sheet by co-extrusion. U.S. Pat. No. 3,892,889 discloses UV stabilized polycarbonate moldings the surfaces of which have been treated with a solution containing a benzotriazole. German DE-OS 3,617,978 discloses co-extruded sheets based on a polycarbonate resin which sheets are covered by a UV absorbing layer made from a branched polycarbonate resin containing the bis-benzotriazole of the present invention. Also relevant is European patent application 110,221 which disclosed a panel consisting of a core layer of polycarbonate containing not more than 0.5 wt. percent of a UV absorber and having on at least one side a coating layer which has been co-extruded with the core and which contains at least 3 percent of a UV absorber. As noted in this prior art, firming of volatile additives and plate out during the extrusion process is a problem which needs to be overcome to provide an extruded sheet without surface imperfections in an environmentally sound process where there is reduced worker exposure to undesirable fumes.